Linear compressor

Abstract

A linear compressor according to the invention is for generating compressed gas and includes two pairs of pistons 608 a , 608 b and cylinders 607 a and 607 b coaxially provided and facing opposite to each other, a shaft 603 having pistons 608 a and 608 b at its ends, coil springs 605 a and 605 b coupled to shaft 603 for returning a piston departed from a neutral point to the neutral point, and a linear motor 613 for causing shaft 603 to axially move back and forth, thereby generating compressed gas alternately in two compression chambers 611 a and 611 b. Thus, the non-linear force of the compressed gas acting upon the pistons may be divided into two/reversed in phase. As a result, as compared to a conventional structure having only a single piston, the motor thrust may be reduced and linearized for the purpose of improving the efficiency. Furthermore, the size of the device may be reduced as well as the vibration/noises caused thereby may be reduced.

What is claimed is:  
     
       1. A linear compressor for generating compressed gas, comprising: 
       a shaft having a piston;  
       a cylinder having a compression chamber accommodating said piston;  
       a body defining said cylinder for accommodating said shaft;  
       a linear motor defined by fixed and movable members coupled to said shaft and said body, respectively, for providing said piston with reciprocating movement, thereby generating said compressed gas in said compression chamber;  
       a first elastic member connected between said shaft and said body for returning said piston departed from a neutral point to said neutral point; and  
       a second elastic member connected between said shaft and said body operative to prevent axial deviation of said shaft.  
     
     
       2. The linear compressor as recited in  claim 1 , wherein 
       a vibrating portion including said pisiton, said shaft, said first elastic member, said second elastic member and said compressed gas has a prescribed resonant frequency, and  
       said linear motor drives said shaft to move back and forth at said resonant frequency.  
     
     
       3. The linear compressor as recited in any one of claims  1  and  2 , wherein 
       said linear motor has a coil fixedly disposed in said body and a permanent magnet fixed to said shaft, and  
       said first elastic member is accommodated within an inner space provided at said permanent magnet.  
     
     
       4. The linear compressor as recited in any one of  claims 1  to  3 , wherein 
       said first elastic member is a coil spring, and said second elastic member is a suspension spring.